A fuel injector for an internal combustion engine is discussed in German patent document DE 40 05 455 A1. There, a piezoelectric actuating element for a valve needle is provided. Furthermore, a chamber filled with fuel is provided, which is sealed via a spring diaphragm, which simultaneously operates as restoring spring for the valve needle.
In the fuel injector of DE 40 05 455 A1 the fuel is spray-discharged from the fuel-filled chamber when the valve needle is actuated. However, when such a known fuel injector is used in a fuel-injection system, the problem arises that, in particular, a starting behavior of an engine is disadvantageous. This problem occurs especially when a mixture of gasoline and alcohol, a diesel fuel or a mixture of diesel and organic fuels is used as fuel.